Java StringBuilder delete()用法及代码示例

StringBuilder类的delete(int start，int end)方法从StringBuilder包含的String中删除从索引start到index end-1的字符。此方法使用两个索引作为参数，第一个开始代表第一个字符的索引，结束索引代表要从StringBuilder包含的String中删除的子字符串的最后一个字符之后的索引，并将剩余的String作为StringBuilder对象返回。

用法:

public StringBuilder delete(int start, int end)

参数：此方法接受两个参数：

start：子字符串的第一个字符的索引。
end：子字符串最后一个字符之后的索引。

返回值：删除子字符串后，此方法返回此StringBuilder对象。

异常：如果start小于零，或者start大于String的长度，或者start大于end，则此方法引发StringIndexOutOfBoundsException。

下面的程序演示StringBuilder类的delete()方法：

示例1:

// Java program to demonstrate 
// the delete() Method. 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        // create a StringBuilder object 
        // with a String pass as parameter 
        StringBuilder 
            str 
            = new StringBuilder("WelcomeGeeks"); 
  
        // print string 
        System.out.println("Before removal String = "
                           + str.toString()); 
  
        // remove the substring from index 2 to 8 
        StringBuilder afterRemoval = str.delete(2, 8); 
  
        // print string after removal of substring 
        System.out.println("After removal String = "
                           + afterRemoval.toString()); 
    } 
}

输出：

Before removal String = WelcomeGeeks
After removal String = Weeeks

示例2:

// Java program to demonstrate 
// the delete() Method. 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        // create a StringBuilder object 
        // with a String pass as parameter 
        StringBuilder 
            str 
            = new StringBuilder("GeeksforGeeks"); 
  
        // print string 
        System.out.println("Before removal String = "
                           + str.toString()); 
  
        // remove the substring from index 8 to 8 
        StringBuilder afterRemoval = str.delete(8, 8); 
  
        // start equal to end so no change in string 
        // print string after removal of substring 
        System.out.println("After removal of SubString"
                           + " start=8 to end=8"
                           + " String becomes => "
                           + afterRemoval.toString()); 
  
        // remove the substring from index 1 to 8 
        afterRemoval = str.delete(1, 8); 
  
        // print string after removal of substring 
        System.out.println("After removal of SubString"
                           + " start=1 to end=8"
                           + " String becomes => "
                           + afterRemoval.toString()); 
    } 
}

输出：

Before removal String = GeeksforGeeks
After removal of SubString start=8 to end=8 String becomes => GeeksforGeeks
After removal of SubString start=1 to end=8 String becomes => GGeeks

示例3:演示IndexOutOfBoundException

// Java program to demonstrate 
// exception thrown by the delete() Method. 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        // create a StringBuilder object 
        // with a String pass as parameter 
        StringBuilder 
            str 
            = new StringBuilder("GeeksforGeeks"); 
  
        try { 
  
            // make start greater than end 
            StringBuilder afterRemoval = str.delete(7, 4); 
        } 
  
        catch (Exception e) { 
            System.out.println("Exception: " + e); 
        } 
    } 
}

输出：

Exception: java.lang.StringIndexOutOfBoundsException

参考：
https://docs.oracle.com/javase/10/docs/api/java/lang/StringBuilder.html#delete(int, int)

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注：本文由纯净天空筛选整理自AmanSingh2210大神的英文原创作品 StringBuilder delete() in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。